Medical pacing wires

ABSTRACT

A medical pacing wire comprising a clamp that is adapted to be moved between an open position and a closed position and further adapted to allow a user to attach an electrode to a living tissue. In particular embodiments, the medical pacing wire may include a memory shape alloy having a memory state, which is adapted to cause the clamp to move from the closed position toward the open position when the memory shape alloy is caused to move from a non-memory state to the memory state. Also, in some embodiments, the clamp may comprise a superelastic material, and the medical pacing wire may be adapted to allow a user to remotely cause the clamp to substantially release the living tissue that has been closed within the clamp without substantially damaging the living tissue.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No.61/451,104, entitled Medical Pacing Wires, filed Mar. 9, 2011, which ishereby incorporated herein in its entirety.

BACKGROUND

Cardiac surgical procedures have become very common worldwide. By someestimates, 700,000 are performed annually in the USA. Despite theircomplexities, the risk associated with these procedures has steadilydeclined over the years. However, the temporary pacing wires that areplaced on essentially every heart at the completion of the procedurehave not improved their safety profile in close to two decades. As amatter of fact, surgeons continue to use temporary pacing wires thatwere designed in 1992. These temporary pacing wires/leads, when removedseveral days post-operatively, continue to pose a significant risk ofbleeding to the patient. Such bleeding could lead, in about 1% of cases,to tamponade and even death. These devices are so hazardous that somesurgeons prefer to refrain from using them rather than expose thepatient to the bleeding risks.

Several different prior art pacing wires will now be discussed forbackground purposes. In various prior art pacing wires, a distal end ofthe pacing wire is secured to the heart with a suture. A few days later,the pacing wire is removed by pulling on the proximal end of the wire,which is outside the patient's chest, in essence tearing the tissueattached to the distal end and pulling it through the chest wall. Themajor complication of such a system is the potential bleedingcomplications that may ensue by ripping a portion of the heart tissue inorder to dislodge the sutured distal end of the device. Another minor,yet annoying, feature of this prior art pacing wire is encountered ifthe surgeon decides to lift the heart and inspect it after securing thepacing wire in place. In such cases, he or she will often dislodge/ripthe distal end of the pacing wire off of the patient's heart, and mustthen reattach the device to the heart. This may lead to intraoperativebleeding that can make the surgery more difficult to complete. Anothershortcoming of this device is that, when securing the distal electrodeto the heart with a suture, bleeding may occur from the suture itself asthe suture passes into the heart tissue. In such cases, additionalsutures may be required to stop the bleeding.

In other prior art pacing wires, the pacing wire's distal pacingelectrode is driven into, rather than sutured to, the heart tissue. Insuch pacing wires, the distal electrode is attached to a helical suturethat has a curved needle at one end. The curved needle is driven intothe heart and pulled through until the distal electrode is embeddedwithin the heart tissue. The curved needle and a portion of the helicalsuture are then cut leaving the distal electrode positioned inside theheart tissue. A few days later, the pacing wire is removed, by pullingon the proximal end of the wire/lead that is outside the patient'schest. In this case, instead of tearing the tissue that is attached tothe distal end of the pacing wire, and pulling the distal electrodethrough the chest wall, the distal electrode slips out of themyocardium/tissue of the heart and is removed. Unfortunately, however,bleeding can still occur from the tract evacuated by the electrode andattached wire with all of the associated morbid consequences includingdeath. Furthermore, this arrangement is also subject to all of the othershortcomings that plague the prior art arrangement discussed above interms of dislodgement and bleeding associated with resecuring theelectrode to the heart.

Yet another prior art pacing wire arrangement calls for securing apermanent clip to the heart that has an antenna (in the form of twoparallel rabbit ears), or a round receptacle through which a pacing wiremay be introduced. The problems with this design are multifold. First,since the electrode and pacing wire are loosely attached together, thepotential for the wire to dislodge from the electrode antenna in such away as to stop pacing is very high as a result of: (1) the beating ofthe patient's heart; (2) the patient's movements; or (3) the patient'srespiratory fluctuations. Also, the permanent electrode isdisadvantageously left on the heart permanently. In addition, securingthe electrode to the heart poses the risk of causing bleeding asdescribed above in regard to the arrangements of FIGS. 1 and 2. Lastly,disengaging the wire from the permanent electrode could potentially behazardous.

In brief, currently known cardiac pacing wires continue to presentsignificant hazards to patients. Accordingly, there is a need forimproved, safer cardiac pacing wires.

SUMMARY

A medical pacing wire according to various embodiments comprises: (1) anelongated flexible conductor (e.g., an insulated wire with two strippedends that serve as electrodes, or any other suitable conductor); (2) aclamp attached to the flexible conductor's distal end; and (3) a needle(e.g., a Keith needle) that is attached to the flexible conductor'sproximal end. In particular embodiments, the Keith needle is scored foreasy removal.

In various embodiments, the clamp includes first and second opposingclamp members and a grip portion that may be used to move the clampbetween: (1) an open position in which the first and second clampmembers are spaced a first distance apart from each other; and (2) aclosed position in which the first and second clamp members are spaced asecond distance apart from each other, the second distance being shorterthan the first distance. The medical pacing wire may be adapted to allowa user to attach an electrode to a living tissue by: (1) moving theclamp into the open position; (2) positioning the clamp so that theliving tissue is positioned between the clamp's first and secondopposing clamp portions; (3) closing the clamp until the first andsecond clamp portions are in the closed position and exert opposingcompressive forces on opposite sides of the living tissue and therebymaintain the electrode in engagement with the living tissue.

In various embodiments, the clamp is adapted to allow a user to remotelycause the clamp to at least substantially release the living tissuewithout substantially damaging the tissue. For example, the clamp may bemade of a material, such as a metal shape alloy, that is configured tochange its shape in response to being exposed to a particular change intemperature or to an electric current. As one example, the clamp is madeof a memory shape alloy, such as Nitinol, that is adapted: (1) to remainin the shape of a clamp at standard animal body temperatures; and (2) torelax into the form of a flexible wire in response to being cooled to atemperature that is a few degrees below standard animal bodytemperatures. This may allow a user to remotely release the clamp fromthe living tissue (e.g., without substantially damaging the livingtissue) by simply subjecting the proximal end of the pacing wire to anappropriate change in temperature. The user may then withdraw the distalend of the pacing wire from the individual's body in the form of alow-profile, flexible wire rather than in the form of a clamp.

In a particular embodiment, the pacing wire may include a clamp and anactuator, the actuator being adapted to respond to a change intemperature to bias the clamp towards an open position from a closedposition. In another embodiment, the pacing wire may include a physicalmechanism (similar to a bike brake cable) that is adapted to allow auser to remotely open and close the clamp from outside a patient's bodywhile the clamp is attached to tissue inside the patient's body.

To use the pacing wire to pace a user's heart, a user (typically acardiac surgeon): (1) passes the Keith needle and the proximal end ofthe pacing wire through the patient's chest wall and skin; (2) attachesthe clamp to a portion of the patient's heart; (3) snaps the Keithneedle off at a score line on the Keith needle; and (4) connects theproximal end of the pacing wire to a pacemaker. The pacemaker is thenused to pace the patient's heart by sending periodic electrical pulsesto the heart through the pacing wire.

Once a physician determines that the patient's heart no longer requirespacing, a user may remove the pacing wire by detaching the clamp fromthe patient's heart, and then removing the clamp through the patient'schest wall. In the case of a pacing wire that has a clamp made from amemory shape alloy, this may be done, for example, by subjecting theproximal end of the pacing wire to a change in temperature (e.g., bysubmerging the proximal end of the pacing wire in liquid nitrogen). Inthis example, due to the wire's thermal conductivity, the clamp'stemperature will soon decrease, which will, in turn, cause the wireforming the clamp to relax from its clamp shape into the shape of aflexible wire. In another example, the change in temperature may beaffected by subjecting the pacing wire to a voltage, which may cause theclamp's temperature to increase, which will in turn, cause the wireforming the clamp to relax from its clamp shape. A user may then removethe wire from the patient's body through the patient's chest wall.

In other embodiments, the clamp may be made from a superelastic materialand the pacing wire may further comprise an actuator in mechanicalcontact with the clamp. In such embodiments, the actuator may be made ofa memory shape alloy adapted to change its shape in response to a changein temperature. In various embodiments, the change in shape may causethe actuator to bias the clamp to an open position, allowing a user toremove the clamp from a piece of tissue to which it was clamped.

In the various embodiments in which a more traditional mechanical clampis used (which is configured to be remotely opened and closed viasuitable mechanical or electromechanical means), the operator simply:(1) uses the mechanical or electromechanical control mechanism torelease the clamp from the patient's heart; and (2) withdraws the wire(including the clamp) through the patient's chest wall. For example, ina particular embodiment in which a bike brake cable is used to remotelycontrol the opening/closing of the clamp, the user may: (1) open theclamp by pushing on the end of the brake cable; and then (2) withdrawthe wire and the clamp from the patient's body through the patient'schest wall.

BRIEF DESCRIPTION OF THE DRAWINGS

Having thus described various embodiments in general terms, referencewill now be made to the accompanying drawings, which are not necessarilydrawn to scale, and wherein:

FIG. 1 is a schematic diagram of a cardiac pacing wire according to aparticular embodiment.

FIG. 2 is a top view of a cardiac pacing wire according to anotherembodiment.

FIG. 3 is a schematic diagram of a pacing wire according to a furtherembodiment.

FIG. 4 is a schematic diagram of a pacing wire according to yet anotherembodiment.

FIG. 5 is perspective view of a pacing wire according to a furtherembodiment.

FIG. 6 is a top view of the pacing wire of FIG. 5 with the pacing wire'sclamp in an open position.

FIG. 7 is a top view of the pacing wire of FIG. 5 with the pacing wire'sclamp in a closed position.

FIG. 8 is a side view of the pacing wire of FIG. 5 with the pacingwire's clamp in the open position.

FIG. 9 is a perspective view of a pacing wire according to yet anotherembodiment.

FIG. 10 is a top view of the pacing wire of FIG. 9 with a clamp in anopen position.

FIG. 11 is a top view of the pacing wire of FIG. 9 with the clamp in aclosed position.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

Various embodiments now will be described more fully hereinafter withreference to the accompanying drawings. It should be understood that theinvention may be embodied in many different forms and should not beconstrued as limited to the embodiments set forth herein. Rather, theseembodiments are provided so that this disclosure will be thorough andcomplete, and will fully convey the scope of the invention to thoseskilled in the art. Like numbers refer to like elements throughout.

Various pacing wires described herein provide improvements over priorart pacing wires. Although, in various examples within this patentapplication, we refer to the heart as the primary organ being paced, itshould be understood that the pacing wires described herein may be usedto pace human or animal tissue other than the heart. For example,various embodiments may be used to pace a patient's central orperipheral nerves and/or the patient's brain. It should be understoodthat the clamp-shaped distal electrode (as described subsequently) canbe configured to any other suitable shape to accommodate various surfaceareas of different organs.

A pacing wire 10 according to a particular embodiment is shownschematically in FIG. 1. In this embodiment, the pacing wire 10 includesan elongated flexible conductor 300 that may comprise, for example, asingle filament conductor (or, alternatively, a multi-filamentconductor) that is insulated except for its proximal end 200 and distalend 400 (which serve as electrodes). The pacing wire 10 furthercomprises a Keith needle 100 that is attached to the flexibleconductor's proximal electrode 200 and that is scored for easy removal.

The flexible conductor's non-insulated distal end 400 comprises a wire(or other structure) that has been engineered and manufactured to assumea certain shape of a clamp as shown, for example, in FIG. 2. It shouldbe understood that the flexible conductor's non-insulated distal end maybe a continuous portion of the flexible conductor 300 or it may beseparate wire (or other structure) that is suitably attached to theflexible conductor 300.

In the embodiment shown in FIG. 2, the clamp 400A (which may, forexample, consist essentially of one or more shape metal alloys) is asingle wire that is shaped to form two, substantially parallel,substantially planar, substantially triangular, clamp portions (e.g.,first clamp portion A-B-C 420A and second clamp portion A¹-B¹-C¹ 430A)that are positioned adjacent a grip 410A that includes wire portions Gand H.

In FIG. 2, the first clamp portion A-B-C 420A is in contact with thesecond clamp portion A¹-B¹-C¹ 430A and both of these wire loops are inan XY plane. Wire portions G and H are in a plane ZY that issubstantially perpendicular to the XY plane. As a result, a user mayselectively separate the clamp portion's respective distal edges (B-Cand B1-C1) from each other by compressing wire portions G and H together(e.g., using a suitable clamp or a thumb and index finger).

Various portions of a pacing wire 10E according to an alternativeembodiment are shown in FIG. 5. In this embodiment, the clamp 400E(which may, for example, consist of or consist essentially of one ormore shape metal alloys) includes: (1) a substantially planar (e.g.,planer), substantially tear-shaped (e.g., tear-shaped) first clampportion 420E; (2) a substantially planar (e.g., planar), substantiallytear-shaped (e.g., tear shaped) second clamp portion 430E that issubstantially parallel (e.g., parallel) to the first clamp portion; and(3) a grip 410E that is substantially in the form of an oval. FIG. 7shows the pacing wire 10E from FIG. 5 in a closed position, in which thefirst clamp portion 420E is in contact with the second clamp portion430E and both clamp portions are in an XY plane. However, the grip 410Eis in the XZ plane, which is substantially perpendicular to the XYplane. As a result, a user may selectively separate the clamp portion'srespective distal edges from each other by compressing the grip 410Etogether (e.g., using a suitable mechanical device or a thumb and indexfinger).

In the embodiments shown in FIGS. 2, 5, and 6, a user may attach thepacing wire's clamp 400 to a portion of a patient's heart by squeezingthe clamp's grip 410 which causes the clamp's opposing clamp portions420, 430 (the clamp's “jaws”) to open. The user then positions the clamp400 so that a small piece of heart tissue is positioned between theclamp's opposing clamp portions 420, 430. The user then slowly releasesthe clamp 400 (which is mechanically biased to urge the opposing clampportions 420, 430 towards each other), until the clamp 400 firmly graspsa small amount of the heart's tissue. In various embodiments, no holesare created in the heart which may minimize or entirely eliminate anybleeding associated with attaching the clamp 400 to the heart. Inparticular embodiments, the jaws of the clamp 400 are engineered toapply enough pressure to hold the tissue non-ischemically, yet firmlyenough to prevent slippage.

By virtue of its design and material composition, in variousembodiments, the clamp 400 can be applied and removed multiple timesduring an operation without injuring the heart or losing the clamp'sgrasping power. In particular embodiments, the proximal end of thepacing wire 10 sits outside the chest and allows a user to pace theheart if and when rhythm disturbances occur.

When it is time to remove the temporary pacing wire 10, the pacingwire's proximal electrode 200 can then be used to make the distalelectrode 400 of the pacing wire, which is shaped as a clamp, changeshape and configuration and become a loose, unshaped (e.g.,substantially straight) wire. This releases the heart tissue from theclamp's grasp and preferably allows for an atraumatic disengagement ofthe clamp 400 and removal of the pacing wire 10 from the patient'schest.

As noted above, a user may selectively change the shape of the clamp 10from a clamp configuration to a loose wire configuration by applying anenergy source to the proximal end electrode 200 of the pacing wire 10,which sits outside the patient's chest. The energy source may forexample, cause a change of the wire temperature of only a few degreesabove or below what can be considered normal body temperature range. Inparticular embodiments, the temperature range (which may be any suitabletemperature range) that makes the clamp-shaped wire assume a morenatural straight wire configuration is determined, for example, by thecomposition of elements that constitute the SMA wire.

One suitable energy source would be one that causes a drop intemperature of the wire by a few degrees below normal body temperature.This can be achieved by safely immersing the proximal electrode of thewire in a cold material, such as liquid nitrogen, for few secondscausing transmittal of the cold from one end of the pacing wire (whichis outside the patient's chest) to the other end of the wire, which ispositioned within the patient's chest. After a predetermined contacttime with the energy source (e.g., 10-20 seconds) cooling of the distalend 400 by a few degrees is achieved and the distal end wire 400 willdenature, lose its grip on the heart, and become flexible enough to beremoved at least substantially atraumatically from the patient's body.

Another example of a suitable energy source would be one that would heatthe wire to a temperature that would be sufficient to cause the wire tochange configuration. For example, bringing a heating filament intocontact with the pacing wire's proximal electrode 200 for a short periodtime (e.g., 10-20 seconds) may cause sufficient heat to be transmittedto the clamp 400 to cause clamp 400 to denature, lose its grip on theheart, and become flexible enough to be removed at least substantiallyatraumatically from the patient's body. Yet another example of asuitable energy source that may heat the wire to a temperaturesufficient to change its configuration may be introducing a voltageacross the pacing wire.

As noted above, in further embodiments, other mechanical arrangementsmay be used to selectively disengage more traditional clamps that may,for example, not be made of materials that change form in response tochanges in temperature. Two such embodiments are shown in FIGS. 8 and 9.

Combination Medical Pacing Wire Clamp

In various embodiments, it may desired for the pacing wire's clamp 400to have two-way motion. In such embodiments, the clamp 400 may have twostable positions. In a first stable position, the clamp 400 may providea substantially firm and safe connection to a tissue (e.g., a hearttissue). In a second stable position, the clamp 400 may be released fromthe tissue before a user removes the clamp 400 from a tissue andeventually from a patient's body with which the tissue is associated.This configuration involving at least two stable positions and two-waymotion may be achieved by combining two shape memory alloy elements, twosuperelastic alloy elements, a mix of at least one superelastic alloyelement and one shape memory alloy element, or any other suitablecombination of materials. Each of the two elements may provide motiontowards either an open or a closed position and may make the clamp 400stable in one of the two stable positions. In particular embodiments,the superelastic element may provide a firm grabbing of the tissue. Invarious embodiments, the clamp may include a shape memory element that,when heated (for example through joule heating), may cause thesuperelastic element to disengage from the tissue. When heating isstopped, the clamp may resume its gripped configuration. In particularembodiments, the clamp 400 may be adapted to repeat the process ofopening and closing the clamp 400 without substantially affecting theability of the clamp 400 to grab and release tissue.

For cardiac pacing, a surgeon may put the pacing wire's clamp 400 on thetissue (e.g., the heart tissue). In various embodiments, the clamp maybe removed and put back without any change in temperature. In particularembodiments, the superelasticity of the clamp 400 may make repeateddeformations possible. At the time of removal of the pacing wire, asmall current may be passed to the shape memory element of the clamp400, which may cause slight heating, which in turn may release the clamp400, leaving the lead wire free to be easily and safely removed from thepatient's body.

In various embodiments of a medical pacing wire 10F, such as theembodiment shown in FIGS. 9-11, the pacing wire's clamp 400F maycomprise two or more distinct pieces of material. In particularembodiments, a first piece may have a shape memory state that biases theclamp 400F toward a closed position as shown in FIG. 11. In variousembodiments, a second piece may have a shape memory state that biasesthe clamp 400F toward an open position as shown in FIG. 10. In variousembodiments, the pacing wire 10F may be adapted to produce conditions toplace the first piece in its shape memory state and take the secondpiece out of its shape memory state in order to close the clamp 400F.

The pacing wire 10F may be further adapted to produce conditions toplace the second piece in its shape memory state and take the firstpiece out of its shape memory state in order to open the clamp 400F. Invarious embodiments, these conditions may include, for example a changein temperature. In particular embodiments, the change in temperature maybe a change from the typical temperature of an animal (e.g., a human) toa temperature above the typical temperature of an animal (e.g., ahuman). In various embodiments, the change in temperature may be achange to a temperature above about 37 degrees Celsius (e.g., thetypical temperature of a human). In a particular embodiment, thetemperature change may be a change to a temperature of between about 40degrees Celsius and about 55 degrees Celsius.

In particular embodiments, the first piece may comprise a superelasticalloy that biases the clamp 400F toward the closed position. The secondpiece, which may be attached (e.g., to) the first piece may comprise amemory shape alloy that biases the clamp 400F toward the open positionin response to being subjected to a change in temperature. An example ofsuch an embodiment is described below.

Embodiments Including a Superelastic Piece that Biases the Clamp Towardsthe Closed Position

In a particular embodiment of a medical pacing wire clamp 400, the firstpiece, which comprises (e.g., comprises, consists of, or consistsessentially of) a superelastic alloy, may be in the shape of a clamp asshown in FIG. 5 or 9. As shown in FIG. 5, the clamp's distal end mayinclude a scissored crossover 440E. Alternatively, as shown in FIG. 9,the clamp 400F may have a substantially U-shaped (e.g., U-shaped) distalend. In other embodiments, the clamp's distal end may be in any othersuitable shape. In various embodiments, as shown in FIGS. 5 and 9, theclamp 400E, 400F may further comprise: (1) a substantially planar (e.g.,planer), substantially tear-shaped (e.g., tear-shaped) first clampportion 420E, 420F; and (2) a substantially planar (e.g., planar),substantially tear-shaped (e.g., tear shaped) second clamp portion 430E,430F that is at least substantially parallel (e.g., parallel) to thefirst clamp portion. In other embodiments, the clamp 400 may include anyother suitable clamp portions.

In the open position shown in FIG. 10, the first and second clampportions 420F, 430F may be spaced apart a distance of between about 0.5mm and about 3 mm. In a particular embodiment, when in the openposition, the first and second clamp portions 420F, 430F may be spacedapart a distance of about 1 mm. In various embodiments, the distancebetween the clamp's distal end 410F and the first and second clampportions' proximal ends may be between about 6 mm and about 17 mm. In aparticular embodiment, the distance between the clamp's distal end 410Fand the first and second clamp portions' proximal ends may be about 11mm. In various embodiments, the clamp's distal end 410F may have adiameter that corresponds to the diameter of a circle whose diameter isbetween about 1.5 mm and about 5 mm.

As shown in FIGS. 9-11, the second piece 450F, which may, in variousembodiments, comprise a memory shape alloy, is substantially helical(e.g., helical) and is disposed about a curved portion of the clamp'sdistal end 410F. In particular embodiments, the metal shape alloy (andany other metal shaped alloy described herein) may be a Nickel/Titaniumalloy, a Copper/Zinc/Aluminum Alloy, a Copper/Aluminum/Nickel Alloy, orany other suitable memory shape alloy. In various embodiments, the innerradius of the substantially helical second piece 450F substantiallycorresponds to (e.g., corresponds to) the radius of the clamp's distalend 410F. As may be understood from FIG. 9, the clamp's distal end 400Fextends through the second piece's substantially helical (e.g., helical)structure and the second piece 450F is wrapped a plurality of timesaround the clamp's distal end 410F. In the embodiment shown in thisfigure, the second piece 450F wraps around substantially all (e.g., all)of the clamp's substantially U-shaped distal end 410F. In otherembodiments, the second piece 450F may wrap around any other suitableportion of the clamp's substantially U-shaped distal end 410F. In theembodiment shown in FIG. 9, the substantially helical second piece issubstantially U-shaped (e.g., U-shaped) when in its memory state andwhen the clamp 400F is in the open position.

In particular embodiments, the second piece 450F is given a shape memorystate of a substantially U-shaped (e.g., U-shaped) helix. In variousembodiments, the second piece is adapted to return to its shape memorystate position in response to a change in temperature (e.g., a change toa temperature above about 45 degrees Celsius or above about 50 degreesCelsius) or to any other suitable stimulus. Once the second piece 450Fis given its shape memory state, it may be wrapped around the clamp'sdistal end 410F as described above. Once wrapped around the clamp'sdistal end 410F, the second piece 450F may be selectively used to biasthe clamp 400F toward the open position (e.g., bias the first and secondclamp portions 420F, 430F away from one another) by selectivelyincreasing the temperature of the second piece 450F. In response to thechange in temperature, the second piece 450F may bias the clamp 400Fwith at least a force sufficient to oppose the first piece's biasing ofthe clamp 400F toward the closed position.

In various embodiments, the pacing wire 10F may include a lead wire thatruns along the length of the pacing wire and that is attached adjacent(e.g., to) the second piece 450F. The lead wire may be a conductive wireand may be adapted to transfer a voltage to the second piece 450F. Thistransfer of voltage may be configured to facilitate a change intemperature of the second piece 450F as described above. In a particularembodiment, a voltage of about 2 volts may be applied to the lead wireto facilitate the change in temperature in the second piece 450F that issuitable to move the second piece 450F from a non-memory state positioninto its memory state position. In other embodiments, other suitablevoltages may be applied to facilitate the change in temperature. Inparticular embodiments, the voltage may be a voltage suitable to changethe temperature in the second piece 450F to a temperature between about45 degrees Celcius and about 55 degrees Celsius.

Embodiments Including a Superelastic Piece that Biases the Clamp Towardsthe Open Position

In alternative embodiments, the first piece (e.g., the clamp 400F) maybias the clamp 400F toward the open position rather than the closedposition. In such embodiments, the second piece 450F may selectivelybias the clamp 400F toward the closed position in response to the secondpiece 450F being subjected to an appropriate stimulus (e.g., anappropriate change in temperature). A clamp with such components may bestructurally similar to (e.g., the same as) the embodiment describedabove. In this alternative embodiment, the second piece 450F may respondto a change in temperature by biasing the clamp 400F toward (e.g., into)the closed position with at least a force sufficient to oppose the firstpiece's biasing of the clamp 400F toward the open position.

Alternative Embodiments

Combination Medical Pacing Wire with Alternate Materials

In particular embodiments, the first piece of the pacing wire's clamp400 may comprise a memory shape alloy, and the second piece may comprisea super elastic alloy. In certain embodiments, both pieces may be memoryshape alloys. In various embodiments, the first and/or second piece maycomprise any material suitable for maintaining a shape memory state.

Continuous Combination Medical Pacing Wire Clamp

In various embodiments, the clamp may comprise a substantiallycontinuous (e.g., continuous) piece of material that combines at least asuperelastic alloy and a memory shape alloy rather than two distinctpieces which separately contain each material.

Alternatively Shaped Second Piece

In various embodiments, the second piece may have a structure other thana substantially helical structure. In such embodiments, the second piecemay comprise, for example, a linear spring, a torsion spring, or anyother suitable structure. In particular embodiments, the second piecemay be disposed on the clamp in a position other than that shown inFIGS. 9-11. In such embodiments, the second piece may be disposed in anysuitable position for biasing the clamp in response to a suitablestimulus (e.g., a temperature change).

Open Clamp Indicator

In various embodiments, the pacing wire's clamp 400 may include a lightthat is configured to indicate when the clamp 400 is in the openposition (e.g., and therefore safe to remove from a patient). Inparticular embodiments, the light may be adapted to turn on or off asthe clamp is in the open or closed position respectively. In otherembodiments, the light may be adapted to change colors in response tothe clamp opening or closing. In other embodiments, the clamp mayinclude any suitable indicator other than a light to indicate that theclamp is in the open or closed position.

CONCLUSION

Many modifications and other embodiments of the invention will come tomind to one skilled in the art to which this invention pertains havingthe benefit of the teachings presented in the foregoing descriptions andthe associated drawings. For example, in various embodiments (including,potentially, certain embodiments described above), the pacing wire'sclamp is made of a metal shape alloy (or other suitable material) that:(1) remains in the form of a clamp when the clamp is at a temperaturethat is within a temperature range that includes both typicaloperating-room temperatures and typical animal body temperatures; and(2) that relaxes into the form of a flexible wire in response to beingcooled and/or heated outside of this range of temperatures. It shouldalso be understood that the invention may take form in a variety ofdifferent mechanical and operational configurations. Therefore, it is tobe understood that the invention is not to be limited to the specificembodiments disclosed and that modifications and other embodiments areintended to be included within the scope of the appended claims.Although specific terms are employed herein, they are used in a genericand descriptive sense only and not for the purposes of limitation.

I claim:
 1. A medical pacing wire comprising: an elongated flexibleconductor; and a clamp comprising a scissored crossover having a firstclamp member and second opposing clamp member, said clamp being adaptedto be moved between: (A) an open position in which said first and secondclamp members are spaced a first distance apart from each other; and (B)a closed position in which said first and second clamp members arespaced a second distance apart from each other, said second distancebeing shorter than said first distance, wherein: said medical pacingwire is adapted to allow a user to attach an electrode to a livingtissue by: (A) moving said clamp into said open position; (B)positioning said clamp so that said living tissue is positioned betweensaid clamp's first and second opposing clamp portions; (C) closing saidclamp until said first and second clamp portions: (i) are in said closedposition, and (ii) exert opposing compressive forces on opposite sidesof said living tissue and thereby maintain said electrode in engagementwith said living tissue; and said medical pacing wire is adapted toallow a user to pace the living tissue by, while said clamp ismaintaining said electrode in engagement with said living tissue,conveying an electrical current through said conductor, into saidelectrode, and into said living tissue; and said medical pacing wire isadapted to allow a user to remotely cause said clamp to at leastsubstantially release said living tissue.
 2. The medical pacing wire ofclaim 1, wherein: said medical pacing wire comprises a memory shapealloy; and said medical pacing wire is adapted to allow a user toremotely cause said clamp to at least substantially release said livingtissue by changing a temperature of said memory shape alloy.
 3. Themedical pacing wire of claim 1, wherein: said medical pacing wirecomprises a memory shape alloy; and said medical pacing wire is adaptedto allow a user to remotely cause said clamp to at least substantiallyrelease said living tissue by transmitting a current through said memoryshape alloy.
 4. The medical pacing wire of claim 1, wherein: saidmedical pacing wire is adapted to allow a user to remotely cause saidclamp to at least substantially release said living tissue withoutsubstantially damaging said tissue.
 5. The medical pacing wire of claim1, wherein: said medical pacing wire comprises a memory shape alloyhaving a memory state; and said medical pacing wire is adapted so thatcausing said memory shape alloy to move from a non-memory state to amemory state causes said clamp to move from said closed position towardsaid open position.
 6. The medical pacing wire of claim 5, wherein: saidclamp comprises a superelastic material; and said memory shape alloy isin mechanical communication with said clamp so that causing said memoryshape alloy to move from a non-memory state to a memory state causessaid clamp to move from said closed position toward said open position.7. The medical pacing wire of claim 6, wherein: said clamp comprises acurved portion that is adapted to be moved between a first curvedconfiguration and a second curved configuration, said second curvedconfiguration being different from said first curved configuration; saidclamp is configured so that moving said curved portion of said clampfrom said first curved configuration into said second curvedconfiguration causes said clamp to move from said closed position towardsaid open position; said memory shape alloy is wrapped a plurality oftimes around said curved portion of said clamp; and said memory shapealloy is adapted so that causing said memory shape alloy to move fromsaid non-memory state to said memory state causes said curved portion ofsaid clamp to move from said first curved configuration to said secondcurved configuration and to thereby move said clamp from said closedposition toward said open position.
 8. The medical pacing wire of claim7, wherein said memory shape alloy is in the form of a wire that, whenin its memory state, is substantially in the form of a helix.
 9. Themedical pacing wire of claim 1, wherein: said medical pacing wirecomprises a memory shape alloy having a memory state; and said medicalpacing wire is adapted so that causing said memory shape alloy to movefrom a non-memory state to a memory state causes said clamp to move fromsaid closed position into said open position.
 10. The medical pacingwire of claim 1, wherein: said medical pacing wire comprises a memoryshape alloy having a memory state; and said medical pacing wire isadapted so that causing said memory shape alloy to move from anon-memory state to a memory state causes said clamp to move from saidopen position toward said closed position.
 11. The medical pacing wireof claim 10, wherein: said clamp comprises a superelastic material; andsaid memory shape alloy is in mechanical communication with said clampso that causing said memory shape alloy to move from a non-memory stateto a memory state causes said clamp to move from said open positiontoward said closed position.
 12. The medical pacing wire of claim 11,wherein: said clamp comprises a curved portion that is adapted to bemoved between a first curved configuration and a second curvedconfiguration, said second curved configuration being different fromsaid first curved configuration; said clamp is configured so that movingsaid curved portion of said clamp from said first curved configurationto said second curved configuration causes said clamp to move from saidopen position toward said closed position; said memory shape alloy iswrapped a plurality of times around said curved portion of said clamp;said memory shape alloy is adapted so that causing said memory shapealloy to move from a non-memory state to a memory state causes saidcurved portion of said clamp to move from said first curvedconfiguration to said second curved configuration and to thereby movesaid clamp from said open position toward said closed position.
 13. Themedical pacing wire of claim 12, wherein said memory shape alloy is inthe form of a wire that, when in its memory state, is substantially inthe form of a helix.
 14. The medical pacing wire of claim 1, whereinsaid clamp consists essentially of said at least one memory shape alloy.15. The medical pacing wire of claim 14, wherein said memory shape alloyis selected from a group consisting of: a Nickel/Titanium alloy, aCopper/Zinc/Aluminum alloy, and a Copper/Aluminum/Nickel alloy.
 16. Themedical pacing wire of claim 3, wherein said clamp consists essentiallyof said at least one superelastic material.
 17. The medical pacing wireof claim 1, wherein said medical pacing wire is adapted to allow a userto remotely cause said clamp to release said living tissue by subjectingat least a portion of said medical pacing wire to a temperature change.18. The medical pacing wire of claim 1, wherein said medical pacing wireis adapted to allow a user to remotely cause said clamp to release saidliving tissue by subjecting at least a portion of said medical pacingwire to an electrical current.
 19. The medical pacing wire of claim 1,wherein said medical pacing wire is adapted to allow a user to remotelycause said clamp to release said living tissue via a remote mechanicalrepositioning of said clamp.
 20. A medical pacing wire comprising: anelongated flexible conductor; a superelastic clamp comprising first andsecond opposing clamp members; and a scissored crossover operativelycoupled to said first and second clamp members, wherein: said clamp isadapted to be moved between: (A) an open position in which said firstand second clamp members are spaced a first distance apart from eachother; and (B) a closed position in which said first and second clampmembers are spaced a second distance apart from each other, said seconddistance being shorter than said first distance, wherein, when saidsuperelastic clamp is in its memory state, said superelastic clamp is insaid closed position; and a memory shape alloy that is attached inmechanical communication with said clamp so that causing said memoryshape alloy to move from a non-memory state of said memory shape alloyto a memory state of said memory shape alloy causes said clamp to movefrom said closed position toward said open position.
 21. The medicalpacing wire of claim 20, wherein: said clamp comprises a curved portionthat is adapted to be moved between a first curved configuration and asecond curved configuration, said second curved configuration beingdifferent from said first curved configuration; said clamp is configuredso that moving said curved portion of said clamp from said first curvedconfiguration to said second curved configuration causes said clamp tomove from said closed position toward said open position; said memoryshape alloy is wrapped a plurality of times around said curved portionof said clamp; and said memory shape alloy is adapted so that causingsaid memory shape alloy to move from said non-memory state to saidmemory state causes said curved portion of said clamp to move from saidfirst curved configuration to said second curved configuration and tothereby move said clamp from said closed position toward said openposition.
 22. A medical pacing wire comprising: an elongated flexibleconductor; a superelastic clamp comprising first and second opposingclamp members; and a scissored crossover operatively coupled to saidfirst and second clamp members, wherein: said clamp is adapted to bemoved between: (A) an open position in which said first and second clampmembers are spaced a first distance apart from each other; and (B) aclosed position in which said first and second clamp members are spaceda second distance apart from each other, said second distance beingshorter than said first distance, wherein, when said superelastic clampis in its memory state, said superelastic clamp is in said openposition; and a memory shape alloy that is attached in mechanicalcommunication with said clamp so that causing said memory shape alloy tomove from a non-memory state of said memory shape alloy to a memorystate of said memory shape alloy causes said clamp to move from saidopen position toward said closed position.
 23. The medical pacing wireof claim 22, wherein said clamp comprises a memory shape alloy.
 24. Themedical pacing wire of claim 22, wherein: said clamp comprises a curvedportion that is adapted to be moved between a first curved configurationand a second curved configuration, said second curved configurationbeing different from said first curved configuration; said clamp isconfigured so that moving said curved portion of said clamp from saidfirst curved configuration to said second curved configuration causessaid clamp to move from said open position toward said closed position;said memory shape alloy is wrapped a plurality of times around saidcurved portion of said clamp; said memory shape alloy is adapted so thatcausing said memory shape alloy to move from a non-memory state to amemory state causes said curved portion of said clamp to move from saidfirst curved configuration to said second curved configuration and tothereby move said clamp from said open position toward said closedposition.
 25. The medical pacing wire of claim 24, wherein said memoryshape alloy is in the form of a wire that, when in its memory state, issubstantially in the form of a helix.